diff options
Diffstat (limited to 'drivers/xen/balloon.c')
| -rw-r--r-- | drivers/xen/balloon.c | 76 |
1 files changed, 46 insertions, 30 deletions
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 5dfd8f8ff07..31ab82fda38 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -39,6 +39,7 @@ #include <linux/kernel.h> #include <linux/sched.h> #include <linux/errno.h> +#include <linux/module.h> #include <linux/mm.h> #include <linux/bootmem.h> #include <linux/pagemap.h> @@ -93,8 +94,8 @@ static unsigned long frame_list[PAGE_SIZE / sizeof(unsigned long)]; #define inc_totalhigh_pages() (totalhigh_pages++) #define dec_totalhigh_pages() (totalhigh_pages--) #else -#define inc_totalhigh_pages() do {} while(0) -#define dec_totalhigh_pages() do {} while(0) +#define inc_totalhigh_pages() do {} while (0) +#define dec_totalhigh_pages() do {} while (0) #endif /* List of ballooned pages, threaded through the mem_map array. */ @@ -154,8 +155,7 @@ static struct page *balloon_retrieve(bool prefer_highmem) if (PageHighMem(page)) { balloon_stats.balloon_high--; inc_totalhigh_pages(); - } - else + } else balloon_stats.balloon_low--; totalram_pages++; @@ -422,7 +422,7 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp) (unsigned long)__va(pfn << PAGE_SHIFT), __pte_ma(0), 0); BUG_ON(ret); - } + } } @@ -501,20 +501,24 @@ EXPORT_SYMBOL_GPL(balloon_set_new_target); * alloc_xenballooned_pages - get pages that have been ballooned out * @nr_pages: Number of pages to get * @pages: pages returned + * @highmem: allow highmem pages * @return 0 on success, error otherwise */ -int alloc_xenballooned_pages(int nr_pages, struct page** pages) +int alloc_xenballooned_pages(int nr_pages, struct page **pages, bool highmem) { int pgno = 0; - struct page* page; + struct page *page; mutex_lock(&balloon_mutex); while (pgno < nr_pages) { - page = balloon_retrieve(true); - if (page) { + page = balloon_retrieve(highmem); + if (page && (highmem || !PageHighMem(page))) { pages[pgno++] = page; } else { enum bp_state st; - st = decrease_reservation(nr_pages - pgno, GFP_HIGHUSER); + if (page) + balloon_append(page); + st = decrease_reservation(nr_pages - pgno, + highmem ? GFP_HIGHUSER : GFP_USER); if (st != BP_DONE) goto out_undo; } @@ -536,7 +540,7 @@ EXPORT_SYMBOL(alloc_xenballooned_pages); * @nr_pages: Number of pages * @pages: pages to return */ -void free_xenballooned_pages(int nr_pages, struct page** pages) +void free_xenballooned_pages(int nr_pages, struct page **pages) { int i; @@ -555,17 +559,40 @@ void free_xenballooned_pages(int nr_pages, struct page** pages) } EXPORT_SYMBOL(free_xenballooned_pages); -static int __init balloon_init(void) +static void __init balloon_add_region(unsigned long start_pfn, + unsigned long pages) { unsigned long pfn, extra_pfn_end; struct page *page; + /* + * If the amount of usable memory has been limited (e.g., with + * the 'mem' command line parameter), don't add pages beyond + * this limit. + */ + extra_pfn_end = min(max_pfn, start_pfn + pages); + + for (pfn = start_pfn; pfn < extra_pfn_end; pfn++) { + page = pfn_to_page(pfn); + /* totalram_pages and totalhigh_pages do not + include the boot-time balloon extension, so + don't subtract from it. */ + __balloon_append(page); + } +} + +static int __init balloon_init(void) +{ + int i; + if (!xen_domain()) return -ENODEV; pr_info("xen/balloon: Initialising balloon driver.\n"); - balloon_stats.current_pages = xen_pv_domain() ? min(xen_start_info->nr_pages, max_pfn) : max_pfn; + balloon_stats.current_pages = xen_pv_domain() + ? min(xen_start_info->nr_pages - xen_released_pages, max_pfn) + : max_pfn; balloon_stats.target_pages = balloon_stats.current_pages; balloon_stats.balloon_low = 0; balloon_stats.balloon_high = 0; @@ -584,24 +611,13 @@ static int __init balloon_init(void) #endif /* - * Initialise the balloon with excess memory space. We need - * to make sure we don't add memory which doesn't exist or - * logically exist. The E820 map can be trimmed to be smaller - * than the amount of physical memory due to the mem= command - * line parameter. And if this is a 32-bit non-HIGHMEM kernel - * on a system with memory which requires highmem to access, - * don't try to use it. + * Initialize the balloon with pages from the extra memory + * regions (see arch/x86/xen/setup.c). */ - extra_pfn_end = min(min(max_pfn, e820_end_of_ram_pfn()), - (unsigned long)PFN_DOWN(xen_extra_mem_start + xen_extra_mem_size)); - for (pfn = PFN_UP(xen_extra_mem_start); - pfn < extra_pfn_end; - pfn++) { - page = pfn_to_page(pfn); - /* totalram_pages and totalhigh_pages do not include the boot-time - balloon extension, so don't subtract from it. */ - __balloon_append(page); - } + for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) + if (xen_extra_mem[i].size) + balloon_add_region(PFN_UP(xen_extra_mem[i].start), + PFN_DOWN(xen_extra_mem[i].size)); return 0; } |